Date: Thu, 1 Nov 2001 18:53:02 +0100 From: Bernd Walter <ticso@cicely8.cicely.de> To: lg@deny.ru Cc: freebsd-hackers@FreeBSD.ORG Subject: Re: Unix Philosophers Please! Message-ID: <20011101185302.A9563@cicely8.cicely.de> In-Reply-To: <200111012029.fA1KTdZ70776@lg.deny.ru> References: <20011101161748.E7563@cicely8.cicely.de> <200111012029.fA1KTdZ70776@lg.deny.ru>
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On Thu, Nov 01, 2001 at 08:29:39PM +0000, lg wrote: > > In short: The data is tranfered into the kernel and dropped there. > my source /usr/src/sys/i386/i386/mem.c [FreeBSD-4.3-RELEASE] > says that data doesnt transfered into kernel. I was looking into -current. Null and *random have been seprarated in -current. > kernel just do: (when you write to device with major 2, minor 2) > .... > c = iov->iov_len; > .... > iov->iov_base += c; > iov->iov_len -= c; > uio->uio_offset += c; > uio->uio_resid -= c; > .... > [ where iov is uio->uio_iov ] > > so data doesnt go anywhere. Sorry - you are right. No data is copied into the kernel as it would be the job of null_write() to do if needed. -- B.Walter COSMO-Project http://www.cosmo-project.de ticso@cicely.de Usergroup info@cosmo-project.de To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message
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